/*! Copyright (c) 2010 Brandon Aaron (http://brandonaaron.net)
 * Dual licensed under the MIT (MIT_LICENSE.txt)
 * and GPL Version 2 (GPL_LICENSE.txt) licenses.
 *
 * Version: 1.1.1
 * Requires jQuery 1.3+
 * Docs: http://docs.jquery.com/Plugins/livequery
 */

(function($) {

$.extend($.fn, {
    livequery: function(type, fn, fn2) {
        var self = this, q;

        // Handle different call patterns
        if ($.isFunction(type))
            fn2 = fn, fn = type, type = undefined;

        // See if Live Query already exists
        $.each( $.livequery.queries, function(i, query) {
            if ( self.selector == query.selector && self.context == query.context &&
                type == query.type && (!fn || fn.$lqguid == query.fn.$lqguid) && (!fn2 || fn2.$lqguid == query.fn2.$lqguid) )
                    // Found the query, exit the each loop
                    return (q = query) && false;
        });

        // Create new Live Query if it wasn't found
        q = q || new $.livequery(this.selector, this.context, type, fn, fn2);

        // Make sure it is running
        q.stopped = false;

        // Run it immediately for the first time
        q.run();

        // Contnue the chain
        return this;
    },

    expire: function(type, fn, fn2) {
        var self = this;

        // Handle different call patterns
        if ($.isFunction(type))
            fn2 = fn, fn = type, type = undefined;

        // Find the Live Query based on arguments and stop it
        $.each( $.livequery.queries, function(i, query) {
            if ( self.selector == query.selector && self.context == query.context &&
                (!type || type == query.type) && (!fn || fn.$lqguid == query.fn.$lqguid) && (!fn2 || fn2.$lqguid == query.fn2.$lqguid) && !this.stopped )
                    $.livequery.stop(query.id);
        });

        // Continue the chain
        return this;
    }
});

$.livequery = function(selector, context, type, fn, fn2) {
    this.selector = selector;
    this.context  = context;
    this.type     = type;
    this.fn       = fn;
    this.fn2      = fn2;
    this.elements = [];
    this.stopped  = false;

    // The id is the index of the Live Query in $.livequery.queries
    this.id = $.livequery.queries.push(this)-1;

    // Mark the functions for matching later on
    fn.$lqguid = fn.$lqguid || $.livequery.guid++;
    if (fn2) fn2.$lqguid = fn2.$lqguid || $.livequery.guid++;

    // Return the Live Query
    return this;
};

$.livequery.prototype = {
    stop: function() {
        var query = this;

        if ( this.type )
            // Unbind all bound events
            this.elements.unbind(this.type, this.fn);
        else if (this.fn2)
            // Call the second function for all matched elements
            this.elements.each(function(i, el) {
                query.fn2.apply(el);
            });

        // Clear out matched elements
        this.elements = [];

        // Stop the Live Query from running until restarted
        this.stopped = true;
    },

    run: function() {
        // Short-circuit if stopped
        if ( this.stopped ) return;
        var query = this;

        var oEls = this.elements,
            els  = $(this.selector, this.context),
            nEls = els.not(oEls);

        // Set elements to the latest set of matched elements
        this.elements = els;

        if (this.type) {
            // Bind events to newly matched elements
            nEls.bind(this.type, this.fn);

            // Unbind events to elements no longer matched
            if (oEls.length > 0)
                $.each(oEls, function(i, el) {
                    if ( $.inArray(el, els) < 0 )
                        $.event.remove(el, query.type, query.fn);
                });
        }
        else {
            // Call the first function for newly matched elements
            nEls.each(function() {
                query.fn.apply(this);
            });

            // Call the second function for elements no longer matched
            if ( this.fn2 && oEls.length > 0 )
                $.each(oEls, function(i, el) {
                    if ( $.inArray(el, els) < 0 )
                        query.fn2.apply(el);
                });
        }
    }
};

$.extend($.livequery, {
    guid: 0,
    queries: [],
    queue: [],
    running: false,
    timeout: null,

    checkQueue: function() {
        if ( $.livequery.running && $.livequery.queue.length ) {
            var length = $.livequery.queue.length;
            // Run each Live Query currently in the queue
            while ( length-- )
                $.livequery.queries[ $.livequery.queue.shift() ].run();
        }
    },

    pause: function() {
        // Don't run anymore Live Queries until restarted
        $.livequery.running = false;
    },

    play: function() {
        // Restart Live Queries
        $.livequery.running = true;
        // Request a run of the Live Queries
        $.livequery.run();
    },

    registerPlugin: function() {
        $.each( arguments, function(i,n) {
            // Short-circuit if the method doesn't exist
            if (!$.fn[n]) return;

            // Save a reference to the original method
            var old = $.fn[n];

            // Create a new method
            $.fn[n] = function() {
                // Call the original method
                var r = old.apply(this, arguments);

                // Request a run of the Live Queries
                $.livequery.run();

                // Return the original methods result
                return r;
            }
        });
    },

    run: function(id) {
        if (id != undefined) {
            // Put the particular Live Query in the queue if it doesn't already exist
            if ( $.inArray(id, $.livequery.queue) < 0 )
                $.livequery.queue.push( id );
        }
        else
            // Put each Live Query in the queue if it doesn't already exist
            $.each( $.livequery.queries, function(id) {
                if ( $.inArray(id, $.livequery.queue) < 0 )
                    $.livequery.queue.push( id );
            });

        // Clear timeout if it already exists
        if ($.livequery.timeout) clearTimeout($.livequery.timeout);
        // Create a timeout to check the queue and actually run the Live Queries
        $.livequery.timeout = setTimeout($.livequery.checkQueue, 20);
    },

    stop: function(id) {
        if (id != undefined)
            // Stop are particular Live Query
            $.livequery.queries[ id ].stop();
        else
            // Stop all Live Queries
            $.each( $.livequery.queries, function(id) {
                $.livequery.queries[ id ].stop();
            });
    }
});

// Register core DOM manipulation methods
$.livequery.registerPlugin('append', 'prepend', 'after', 'before', 'wrap', 'attr', 'removeAttr', 'addClass', 'removeClass', 'toggleClass', 'empty', 'remove', 'html');

// Run Live Queries when the Document is ready
$(function() { $.livequery.play(); });

})(jQuery);